Imagine you have a pair of magical dice. You take one die to school, and your friend takes the other die to the other side of the world. Whenever you roll your die and get a 6, your friend's die magically and instantly also rolls a 6. They are perfectly synced up, no matter how far apart they are. In the strange world of quantum mechanics, this kind of connection is real, and it's called quantum entanglement.

Spooky Action at a Distance

Albert Einstein famously called this "spooky action at a distance." He was uncomfortable with the idea that two particles could communicate faster than the speed of light. However, decades of experiments have proven that entanglement is a real phenomenon. When two particles become entangled, their properties are linked. If you measure the spin of one electron and find it pointing "up," you instantly know the other entangled electron will be pointing "down," even if it's light-years away.